Telephone-transmitter.



Patented Dec. 4, I900.

A. 'srn omasna.

TELEPHONE TRANSMITTER.

(Applicntiop filed Feb. 24, 1900.)

(No Model.)

"W1 ESE'EE Egan E EIMB as A ugi NITED STATES PATENT OFFICE.

ALFRED STROMBERG, OF CHICAGO, ILLINOIS.

TELEPHONE-TRANSMITTER.

SPECIFICATION forming part of Letters Patent N 0. 662,985, dated December 4, 1900.

Application filed February 24, 1900. berial No. 6,845. (No model.)

To aZZ whom it may concern:

Be it known that I, ALFRED STROMBERG, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented acert-ain new and useful Improvement in Telephone-Transn1itters, (Case No. 4,) of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to telephonic apparatus, and more particularly to battery-transmitters; and the invention has for-its object the construction of an improved form of transmitter serving to create voice-currents to be transmitted to communicating receivers.

More particularly, my invention has forits object the construction of an improved form of battery-transmitter employing electrodes that are capable of varying the resistance of the transmitter-circuit without having the pressure between the electrodes varied.

To this end myinven tion comprises a longitudinally or substantially rectilineally reciprocating electrode in contact with the second electrode, the longitudinally reciprocating electrode being moved by the action of the sound-waves to bring more or less of its asso ciated electrode in engagement therewith without varying the pressure :betwfeenthe electrodes. o p

In the preferred embodiment of myinvention I employ as the reciprocating electrode a stem of metal projecting from a diaphragm and surround the said stem by comminuted solid materiallforming an electrode, (the reciprocatingelectrode,) the stem passingthrough a Wallofareceptacleincluding'thecomminuted electrode and by its longitudinal reciprocation engaging more or less of the com minuted electrode, thereby to vary the resistance of the transmitter-circuit. To secure perfect operation of the reciprocating electrode, I preferably provide a continuation of the said stem, formed of insulating material conforming thereto in cross-section, this insulatingstem passing throughthe opposite wall of the receptacle containing the comminuted electrode,so that as the metal and insulating parts are moved back and forth the arrangement of the particles of the comminuted electrode is not materially disturbed. The receptacle that I preferably employ for containing the com minuted electrode is cylindrical and made of metal, and the comminuted electrode is preferably in the form of capbon granules.

I will describe my invention more particu larly by reference to the accompanying drawings, illustrating the preferred embodiment thereof, in whicl1-- Figure 1 is a plan view of my improved transmitter, the connections of the transmitter-circuit and the arrangementof the receiver being diagrammatically indicated. Fig. 2 is a View illustrating'a modification of the structure shown in Fig. l, circuit connections of the apparatus being diagrammatically indicated. Fig. 3 is a sectional View on line 3 3 of Fig. 1. Fig. 4c is a sectional view on line 4 4 of Fig. 1. Fig. 5 is a sectional view on line 5 5 of Fig 1.

Like parts are indicated by similar letters of reference throughout. the diiferent views.

An important feature of the transmitter of my invention is to secure a battery-transmitter whose electrodes are actuated by soundvWaves to vary resistance in the transmittercircuit without having the pressure between the electrodes varied One of the electrodes is preferably in the form of carbon granules a, contained Within a vessel 19, preferably held stationarily in position. The containing vessel Z) is preferably in the form of a metal cylinder having holes in its end walls,.through which the longitudinally or rectilineally reciprocating stem may move, rings a of suitable packing, preferably plush, surrounding the holes in the end wallsof the cylindrical vessel to prevent the carbon granules from passing out at these holes. The cylindrical containing vessel is rigidly secured in place upon asupport d. I do not wish to be limited, however, to the particular electrode that is longitudinally reciprocated. The diaphragm e is anchored at its periphery, and a mouthpiece f is placed before the diaphragm. An electrode g, preferably of metal, is attached to the diaphragm, this electrode, as indicated, being in the form of acylindrical stem. The cylindrical stem is provided with a continuation g of insulating material, preferably conforming to the metal portion of the stem in cross-section. Sections 9 and g are preferably of uniform cross-section throughout, so

that as those portions are reciprocated longitudinally pressure between the same and the engaging electrode a will not be varied. It will be apparent that as the electrode 9 is moved back and forth through the action of sound-waves upon the diaphragm to which the same is attached the area of contact of its surface in engagement with the comminuted electrode will vary, the extension g serving as a means for preventing a material disarrangement of the carbon particles. The portions g and g are preferably confined to a fixed straight line of travel.

In the form illustrated in Fig. l I preferably make the electrode g of large cross-section, so that longitudinal movement thereof due to sound-waves will cause sufficient change in the resistance of the transmittercircuit to secure effective operation of the transmitter.

In Fig. 1 the electrode 9 is illustrated as mounted directly upon the diaphragm and as being immovable with relation thereto. It may be desired to secure a greater movement of the electrode g longitudinally with respect to the, movement of the transmitterdiaphragm, for which purpose the construction illustrated in Fig. 2 may be employed, wherein the electrode 9 is connected with the diaphragm through a lever h, pivoted between its ends, the diaphragm being linked with the shorter arm of the lever, while the electrode is linked to the longer arm of the lever.

I have illustrated one type of several types of transmitter-circuits in the drawings that may be employed in connection with my invention. One terminal of the battery is shown as connected with the metallic containing vessel b, and thereby with the comminuted carbon in electrical contact therewith, while the other terminal of the battery is adapted to be united with the electrode g, a primary coil Z being adapted for connection between the battery and the electrode g. A secondary m is shown in circuit with the receiver at, a switchhook 0 serving to include both limbs 19 of a telephone-line that may extend, for example, to an exchange in circuit with the secondary coil and the receiver when the receiver is removed from the switch-hook. The switchhook also serves to close the transmitter-circuit when the receiver is removed.

In accordance with the preferred embodiment' of my invention (illustrated in Fig. 1) the insulating portion 9 is interposed between the electrode 9 and the diaphragm, by which arrangement I am enabled to have fainter sounds accompanied bylower resistance in the transmitter-circuit than that which accompanies the louder sounds, or, in other words, the area of contact between the electrodes of the transmitter is decreased upon an increase in the force of the sound-waves, and a relative increase of the area of contact between the electrodes is effected upon a decrease in the force of sound-waves. This arrangement secures a sensitive transmitter in which a delicate adjustment of the transmitter-diaphragm is not absolutely essential to secure its perfect operation.

I have herein shown and particularly described the preferred embodiment of my invention; but modifications may be readily made from the precise embodiment of the invention herein shown without departing from its spirit, and I therefore desire to secure protection broadly upon the invention herein disclosed.

In some of the claims I have spoken of a solid electrode or an electrode ofsolid material to distinguish from a liquid. 7

lrVhile I have shown a well-known local transmitter-circuit with a battery for supplying the same with current at the substation, I do not wish to be limited to the precise form of transmitter-circuit herein illustrated, as other circuits maybe employed without departing from the spirit of the invention.

While I have shown the comminuted electrode as being stationary and the electrode engaging the same as being longitudinally movable, I do not wish to be limited to this precise arrangement; but,

Having thus described my invention, I claim as new and desire to secure by Letters Patent- I 1. In a battery telephone-transmitter, the combination with an electrode of solid material, of a second electrode of solid material, and means for effecting a substantially rectilineal reciprocation of one of the electrodes through the agency of soundwvaves, without subjecting the first-aforesaid electrode to varying pressure, substantially as described.

- 2. In a battery telephone-transmitter, the combination with an electrode, of a second comminuted electrode, and means for effectin g the substantially rectilineal reciprocation of one of said electrodes through the agency of sound-waves, substantially as described.

3. In a battery telephone-transmitter, the combination with a stem formed in sections of conducting and insulating material, the conducting material constituting an electrode of the transmitter, of a second electrode of solid material in engagement with the con-v ducting and insulating portions of, the said stem, and means for effecting the substantially rectilineal reciprocation of one of the electrodes through the'agency of so rind-waves, substantially as described.

a. In a battery telephone-transmitter, the combination with a stem formed in sections of conducting and insulating material, the conducting material constituting an electrode of the transmitter, of a second comminuted electrode in engagement with the conducting and insulating portions of the said stem, and means for effecting the substantially rectilineal reciprocation of one of the electrodes through the agency of sound-waves, substantially as described.

5. In a battery telephone-transmitter, the combination with a reciprocating electrode of a second comminuted electrode in contact therewith, and means for eifecting the substantially rectilineal reciprocation of the firstaforesaid electrode through the agency of sound-waves without varying the pressure between the electrodes, substantially as described.

6. In a battery telephone-transmitter, the combination with an electrode, of a second comminuted electrode, means for effecting the substantially rectilineal reciprocation of one of said electrodes through the agency of sound-waves, and a containing vessel for the comminuted electrode, the comminuted electrode surrounding the remaining electrode, substantially as described.

'7. In a battery telephone-transmitter, the combination with a stem formed in sections of conducting and insulating material, the conducting material constituting an electrode of the transmitter, of a second comminuted electrode in engagement with the conducting and insulating portions of the said stem, means for efiecting the substantially rectilineal reciprocation of one of the electrodes through the agency of sound-Waves, and a containing vessel for the comminuted electrode, the comminuted electrode surrounding the remaining electrode, substantially as described.

8. In a battery telephone-transmitter, the combination with a reciprocating electrode of a second comminuted electrode in contact therewith, means for efiecting the substantially rectilineal reciprocation of the firstatoresaid electrode through the agency of sound-waves without varying the pressure between the electrodes, and a containing vessel for the comminuted electrode, the comminuted electrode surrounding the remaining electrode, substantially as described.

9. In a battery telephone-transmitter, the combination with a diaphragm to be actuated by sound-waves, of a substantially rectilineal reciprocating electrode actuated thereby, a

second electrode engaging the reciprocating electrode, and means whereby the resistance of the circuit including the said electrodes may be varied without subjecting the second electrode to varying pressure.

10. In a battery telephone-transmitter, the combination with a diaphragm to be actuated by sound-waves, of a substantially rectilineal reciprocating electrode actuated thereby and a second comminuted electrode engaging the reciprocating electrode, substantially as described.

ll. In a battery telephone-transmitter, the combination with an electrode of solid material, of a second electrode of solid material, and means for effecting a substantially rectilineal reciprocation of one of the electrodes through the agency of sound-waves, without varying the pressure between said electrodes, the electrodes being so relatively disposed as to have the area of contact between the same decreased upon an increase in the force of sound-waves, and to have a relative increase of the area of contact between the electrodes effected upon a decrease in the force of the sound-waves, substantially as described.

12. In a battery telephone-transmitter, the combination with an electrode, of a second comminuted electrode, and means for effecting a substantially rectilineal reciprocation of one of said'electrodes through the agency of sound-waves, the electrodes being so relatively disposed as to have the area of contact between the same decreased upon an increase in the force of soundwaves, and to have a relative increase of the area of contact between the electrodes effected upon a decrease in the force of the sound-waves, substantially as described.

13. In a battery telephone-transmitter, the combination with a stem formed in sections of conducting and insulating material, the conducting material constituting an electrode of the transmitter, of a second electrode of solid material in engagement with the conducting and insulating portions of the said stem, and means for effecting the substantially rectilineal reciprocation of one of the electrodes through the agency of sound-waves, the electrodes being so relatively disposed as to have the area of contact between the same decreased upon an increase in the force of sound-waves, and to have a relative increase of the area of contact between the electrodes eifected upon a decrease in the force of the sound-Waves, substantially as described.

14. In a battery telephone-transmitter, the combination with an electrode, of a second comminuted electrode, a diaphragm to which one of the electrodes is secured, and means interposed between the said diaphragm and its attached electrode to effect a greater substantially rectilineal reciprocating movement of said electrode with relation to the movement of the diaphragm, substantially as described.

15. In a battery telephone-transmitter, the combination with an electrode, of a second comminuted electrode, and means for effect-- in g the substantially rectilineal reciprocation of one of said electrodes through the agency of sound-waves, without subjecting the comminuted electrode to varying pressure, substantially as described.

16. In a battery telephone-transmitter, the combination with an electrode, of a portion of insulated material united therewith, a second electrode in engagement with the aforesaid electrode and the said portion of insulating material, and means for effecting the sub-' stantially rectilineal reciprocation of one of the electrodes through the agency of soundwaves, substantially as described.

In witness whereof I hereunto subscribe my name this 22d day of February, A. D. 1900.

ALFRED STROMBERG.

Witnesses:

GEORGE L. ORAGG, CHARLES E. HUBERT. 

